Franz lehmann



(No Model.)

P. LEHMANN.

DRIVING GEAR FOR SEWING MACHINES.

No. 256,842. Patented Apr. 25, 1882.

WIVM M t N PETERS, Fmu-mhn n her. Wmhinglon, D. c,

UNITED STATES PATENT OFFICE.

FRANZ LEHMANN, OF BERLIN, GERMANY.

DRIVING-GEAR FOR SEWING-MACHINES.

SPECIFICATION forming part; of Letters Patent No. 256,842, dated April 25, 1882.

Application filed September 15, 1881.

To all whom tt may concern Be it known that I, FRANZ LEHMANN, of Berlin, in the Empire of Germany, have invented certaiu new and useful Improvements in Driving- Gear for Sewing- Machines, of which the following is a specification.

In the use of sewing-machines operated by foot-power it becomes often desirable to drive the same during more or less long periods by hand to produce certain classes of work. For this purpose a handle is generally attached to the fly-wheel of the machine-that is to say, to the heavy driving-pulley on the main shaft of the sewing-machine proper-the belt or cord from the large pulley on the crank-shaft being disconnected when it is desired to drive the machine by hand. This arrangement has the disadvantage that the motion of the, machine when driven by hand is much slower than is in most cases desirable. 1 have devised an arrangementot'parts whereby hand or footpower may be applied without reducing in either case the speed of the machine. The invention may be carried out either in the shape of an attachment to existingmachines, or the device may form part of the general construction in the building ot'new machines. I will describe itas applied to what is known as a Singer Shuttle-Machine, and have so represented it in the accompanying drawings, in which Figure 1 is a side elevation of the rear part of a sewing-machine provided with my device, certain parts being shown in section. Fig. 1 shows in side elevation, in section, and in end elevation certain parts on a larger scale than Fig. 1. Fig. 2 is an end elevation of theparts shown in Fig. 1. Fig. 3 is a plan thereof partly insection 5 and Fig. 3 shows in section and in elevation, on alarger scale, certain parts in a position corresponding to Fig. 3. These drawings form a part of this specification and (No model.) Patented in Germany November 19, 1850.

through the bushing a, and is supported therein, as shown. screwed into the end of shaft 1), so as to overhang the bushing or hearing a. This pin 0 supports a clutching head or button, 0. The pin 0 is formed with a round part, c, anda .flattened part, 0 the width of thelatter being.

greater than the diameter of part c. The innerpartofbutton O,which faces the fly-wheelA, is formed with a central hole of the same diameter as part a, so as to admit of both a sliding and turning motion of the button 0 thereon, and in this holeare-formed two feather-grooves ot' sufiicient size to accommodate theflattened part c of pin 0. ton G has a chamber in which .plays a spiral spring encircling the part c, and which abuts on one side against the shoulder of the chamber in the button (1, and on the other side against a head fixed upon the pin a, as shown, and thus tends to force the button 0 constantly toward the fly-wheel B. The inner face of the button 0 is formed with two clutch-claws, d d,

capable of engaging with two correspondingclaws, d d, on the face of the fly-wheel.

It is a ring ofinternal teeth, which may either be formed in one with the fiy-wheel or be fixed thereto in any suitable reliable manner.

f is a shaft supportedin a bearing fixed upon the neck of the machine, and in another hearing formed on the standard B. This shaft is capable of a turning and an endwise motion in its bearings, and carries two gear-wheels, g and h, the first of which, g, engages with a wheel, 2', fixed upon the main shaft 1), while the other, h, engages in the ring of teeth when the shaft is moved toward the right in Fig. 1.,

while in the position shown in the figure both wheelsg and h are not affected by or do not affect the corresponding wheels, 2' and k. In either of these two positions the shaftf may be reliably held by turning the lover I so as to engage the same in either of the grooves m or m turned into the shaft f;

D is the ordinary spooling attachment of a Singer machine.

When the parts are in the position shown in Figs. 1, 1, and 2-that is to say, with the clutch O engaged and with the gear-wheels g and h disengaged-the machine is ready to be A peculiarly-shaped pin, 0, is'

The rear or other part of but- ICO operated by foot-power, the pulley A transmitting the motion to the clutch-button C, from which it is inturn transmitted throughthe flattened part 0 0i the pin 0 to the main shaft 1).

When it is desired to drive the machine by hand with about the same velocity as by footpower the belt is taken off the pulley A, the clutch-head O is drawn backward and turned quarter round, so that when released it abuts against the shoulders of the flattened part 0 of pin 0, thus holding its claws d d out of engagement from the claws d d of the pulley B; then the shaftfis liberated by turningthe lever 1 and noved toward the right,thus engaging wheel h with k and wheel g with 2f.- On loeking the shaft f in this new position by means of lever I, as above described, handpower may be applied to the pulley B by means of the crank handle, whereby the shaft 1) may be driven at about the same speed as before, the motion being transmitted from the pulley A through R, 71,, f, g, and 6.

When it is desired to drive the machine slowly by hand the clutch O is kept engaged with the pulley A, and thewheelsg hare maintained out of engagenlentwith their respective wheel-s i and 7c, the same as for operating by foot-power, the belt being of course taken off. For spooling both the clutch O and the wheels gand h are disengaged, whereupon the spooling may be effected by foot or hand power without setting any part of the sewing mechanism in motion.

Modifications may be made in the details without departing from the general principles of theinvention. The pin 0, instead of having a flattened part, 0 may have afeather extending a corresponding partot' its length, the proportions of the wheels 9 h '5 It may be varied to a considerable extent, or more wheels, 9 i, of different proportions, may be used, so as to obtain' various speeds, according to which set is engaged, care being taken to make the ring of teeth is sufficiently wide to maintain the wheel h. engaged therewith as long as any of the sets 9 i are engaged. The teeth It may be internal or external. The arm a, connecting the second bearingof the shaft f with the standard B, may be omitted. I prefer, however, the construction shown as affording great rigidity of the fixed parts.

I claim as my invention- 1. In a sewing-machine, the fly-wheel A, mounted concentrically with the main shaft 1) on a bushing, 01, fixed to a rigid part of the frame, in combination with said mainshaft and said bushing, and with a clutch, G,oarried on an extension of the main shaft and capable of being engaged with and disengaged from the 7 pulley A, substantially as herein specified.

2. As a sewingmachine, the flywhecl A, mounted concentrically with the main shaft b, but capable of turning independently thereof, in combination with said main shaft, with oscillating gearing between the two, means for engaging and disengaging such gearing, and with a clutch, G, substantially as and for the purposes herein specified.

3. As a sewingmachine attachment, the standard B, having a bushing, a-,capableof receiving the fly-wheel A, in combination with the clutch O c for connecting the fly-wheel and main shaft of the machine, substantially as herein specified.

4. As a sewing-machine attachment, the standard B, having the bushing a, and a suitble hearing or bearings for a longitudinallylnovable shaft carrying accelerating gearing, in combination with such shaft and gearing, and with a toothed circle, k, revolved by the fly-wheel, the gear-wheel i, and the clutch 0, all arranged to serve relatively to each other and to the main shaft 1) of the machine, substantially as and for the purposes herein specified.

In testimony whereof I have hereunto set my hand at Berlin, Prussia, this eleventh day of March, one thousand eight hundred and eighty-one, in the presence of two subscribing witnesses.

FRANZ LEHMANN.

Witnesses:

O. GRONERT, BERTHOLD Bot. 

